Remotely powered electronic devices and related systems for supplying power to and receiving stored information from such devices are known. For example, U.S. Pat. No. 5,009,227 issued to Geiszler et al., entitled Proximity Detecting Apparatus, discloses a remotely powered device that uses electromagnetic coupling to derive power from a remote source and then uses both electromagnetic and electrostatic coupling to transmit stored data to a receiver often collocated with the remote source. These systems are also known as radio frequency identification ("RFID") systems. Such RFID systems are usable in numerous applications, including, for example, in inventory control, livestock control, and sentry systems. Additionally, radio frequency identification tags are used in electronic article surveillance ("EAS") systems, such as those used at exits in retail establishments where merchandise is sold.
Typically, RFID systems include an integrated exciter/receiver and RFID tags. The exciter/receiver generates an excitation field and detects or receives a response field. The RFID tags are remotely powered by the excitation field and produce the response field. Some RFID systems include a keyboard or keypad that is hardwired to an exciter/receiver. The keypad is used, for example, to enter a code to permit entry to a secure area. Use of a keypad advantageously expands the capability and flexibility of the RFID system.
Unfortunately, hardwired keypads or keyboards require modification to an exciter/receiver for use therewith or design of an exciter/receiver specifically for attachment to a hardwired keyboard. This is an obvious disadvantage, particularly where it is desirable to add the keyboard to an existing RFID system.
Therefore, a need exists for a keyboard that is readily adapted to or retrofit with an exciter/receiver of an RFID system without adding wires to the system.